ABSTRACT
A video-rate optical phase conjugator using an image sensor and a liquid crystal panel that operated at 30 Hz was developed and its temporal characteristic was studied. Strong air turbulence of atmospheric structure constant, Cn=6.3×10(-7) [m(-1/3)], was successfully compensated, reducing beam dancing by a factor of 2. To our knowledge, this is the first report demonstrating real-time wavefront correction by digital phase conjugation using commercial devices.
ABSTRACT
We investigate the tracking ability of an optical phase conjugator using a commercial CCD array and a projector LCD panel. This system allows one to use two separate laser oscillators for capturing interference patterns and generating phase conjugate light. Since a long coherence length is not required for the latter part, amplification of the phase conjugate light can be easily attained by using a laser oscillator for high-power applications such as machining. The wavelengths of the two laser oscillators can be independently chosen. For our experimental configuration an amplification factor of 7.8×10(4) is theoretically possible. Also, a formula for the maximum tracking range is derived. The proposed system is particularly suitable for power transmission by light.
ABSTRACT
A solar-pumped 100 W class laser that features high efficiency and low cost owing to the use of a Fresnel lens and a chromium codoped neodymium YAG ceramic laser medium was developed. A laser output of about 80 W was achieved with combination of a 4 m(2) Fresnel lens and a pumping cavity as a secondary power concentrator. This output corresponds to 4.3% of conversion efficiency from solar power into laser, and the maximum output from a unit area of Fresnel lens was 20 W/m(2), which is 2.8 times larger than previous results with mirror-type concentrator.
